The invention relates to a sealing passage arrangement for a pipeline through a wall aperture in a housing exposed to lubricant medium, said housing being attachable so as to be sealed by a housing edge delimiting the open side of the housing on a receiving surface of an internal-combustion engine, having a seal element made of elastomer material which tightly closes the wall aperture and is penetrated by the pipeline connected inside the housing.
A pipe passage arrangement of this type is known from Austrian Patent Specification No. 372,162. In this construction the wall aperture provided in the housing for the passage of a fuel pipe is constructed as a cylindrical bore. The latter is penetrated by a cap screw receiving the end piece of the fuel pipe which is to be connected inside the housing to a pump-nozzle unit of a fuel-injection internal-combustion engine, for example, which cap screw maintains the tapered end part of the fuel pipe in engagement with a tapered seat of a connecting piece of the pump-nozzle unit.
A bellows seal inserted to form a seal into the wall aperture and enclosing the cap screw to form a seal serves as a seal element for the sealed closure at the wall aperature of the housing space which is generally filled with lubricant medium mist.
This type of pipe passage makes it necessary to equip the housing with a removable cover in order to permit rapid access in case of need to the components accommodated inside the housing, such as the camshaft, its bearings or rocker levers, because otherwise the fuel pipes, a plurality of which are generally provided; have to be demounted to enable the housing to be removed from the cylinder head.
This construction furthermore permits all the fuel pipes to be connected to the individual pump-nozzle units only after the housing has been placed on the cylinder head. Lastly, the assembly of the bellows which have to be attached so as to form a seal in the wall aperture is complicated and time consuming.
It is therefore an underlying object of the invention to provide a sealing pipe passage arrangement which permits a one-part housing construction, the demounting of the housing without stripping down the pipeline, the connection of the latter to the unit before the assembly of the housing, and an easily effected arrangement of the seal element in the wall aperture without additional measures to seal the pipe at the point where it penetrates the seal element.
This object is achieved according to the invention by providing an arrangement wherein the wall aperture starts from the housing edge and extends into the housing wall, wherein the seal element includes a first part and a second part, the first part being retained upright on the receiving surface and being releasably in engagement with the wall aperture which receives the second part, and wherein the two mutually abutting first and second seal element parts enclose the pipeline to form a seal between themselves.
In the construction according to the invention an open-edged wall aperture is provided at the edge of the housing to receive a two-part seal element, one part of the seal element being arranged on the receiving surface of the internal-combustion engine and the other part in the wall aperture. It is therefore possible to connect the pipeline in a space enclosed by the housing even before the housing is assembled. Then during the assembly of the housing the pipeline already fitted and also the part of the seal element provided on the internal-combustion engine come into engagement with the open-edged wall aperture, whereby the wall aperture becomes tightly closed and the pipeline simultaneously becomes clamped to form a seal between the two seal element parts. For purposes of disassembly it is only necessary to release the housing from the internal-combustion engine and lift it off, in which case the seal of the wall aperture is necessarily simultaneously broken again.
In addition to the pipe passage according to Austrian Patent Specification No. 372,162, from which the invention starts, a pipe passage is already known from German Published Unexamined Application No. 3,524,278, which exhibits a seal element for at least one pipeline which is slidable into a wall aperture and encloses the relevant pipeline. In this case, however, the seal element as a whole is engaged in the wall aperture and is slitted along its length for the insertion of the pipeline. There is therefore no tight closure of the housing.
U.S. Patent Specification No. 2,534,690 has as its object in FIG. 7 a pipe passage in which two seal-forming mutually abutting sections of a seal element are already inserted into an open-edged wall recess.
In this case, however, each section receives a pipeline, for which purpose they are slitted, and on the other hand two seal element sections are retained at a distance from the open-edged side of a wall recess by means of a retaining clip in the latter. Therefore, on the one hand, the wall aperture is not closed tightly, and on the other hand, no automatically dividing seal element exists in the case of a housing displacement in the longitudinal direction of the wall recess.
Lastly, German Patent Specification No. 958,671 discloses a tight passage for pipe banks which exhibits a two-part seal element for each pipe, the sections of which can be placed together under pressure and thereby enclose the relevant pipe to form a seal.
Although this construction produces a sealed pipe passage through a housing wall, nevertheless one or more two-part seal elements have to be arranged for this purpose in a tensioning frame, which in turn has to be inserted into a closed-edged wall recess. It is therefore impossible to demount the housing without previously removing the pipe or pipes.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.